The invention relates to medical devices and can be used in cardiac surgery for replacement of the diseased native aortic and mitral heart valves in humans. This invention can also be successfully used for replacement of the diseased tricuspid valve or pulmonary valve.
There is a certain heart valve prosthesis (SU 1761132) comprising an annular housing, a disc occluder pivoting eccentrically within the housing between an open position, which allows the passage of the direct blood flow, and a closed position, which restricts the blood backflow, a cuff fixed between projections located at the housing faces having a mounting surface which comes into contact with the cardiac tissues, an inner surface embracing the housing, and an outer surface which comes into contact with the blood flow. The cuff is made of a woven material and is permanently attached to the housing by means of suture bandage rings.
There is a certain heart valve prosthesis (U.S. Pat. No. 5,137,532) comprising an annular housing, an occluder in the form of two leaflets pivoting eccentrically within the housing between an open position which allows the passage of the direct blood flow, and a closed position which restricts the blood backflow, a cuff permanently attached to the projection located at the outer housing surface by means of bandage rings. The cuff has a mounting surface which comes into contact with the cardiac tissues, an inner surface embracing the housing, and an outer surface which comes into contact with the blood flow.
There is a certain heart valve prosthesis (U.S. Pat. No. 4,477,930) comprising an annular housing, an occluder in the form of three elastic leaflets made of biological material which move between their open and closed positions to allow the passage of the direct blood flow and restrict the blood backflow. The housing is made of elastic polymeric material or metal, which deforms during leaflet closure and compensates loads working on the leaflets. A cuff permanently attached to the outer housing surface by means of sutures has a mounting surface which comes into contact with the cardiac tissues, an inner surface embracing the housing, and an outer surface which comes into contact with the blood flow.
All three the above-mentioned prostheses represent typical models of various heart valve prostheses which are used widely and successfully throughout the world. But all of them have a common shortcoming, that is, that their cuff is permanently attached to the housing and that its attachment is carried out in factory settings. In this connection it is possible to damage the prosthesis during its implantation when suturing the cuff to the fibrous ring. And during reimplantation of the prosthesis it is necessary to remove the prosthesis together with the cuff from the fibrous ring and this is a very traumatic operation requiring additional time for surgery on the non-beating heart. These manipulations increase the risks of operative complications and patient death.
There is a certain heart valve prosthesis (RU Patent Application No. 2007127767, now RU Patent No. 2 350 300) comprising an annular housing having at least one projection along its outer perimeter, an occluder which restricts the blood backflow, and a cuff made of porous material, for example, synthetic fabric, and having a mounting surface which comes into contact with the cardiac tissues and an outer surface which comes into contact with the blood flow. The cuff has a stent forming an opening for installation of the annular housing of the prosthesis, supporting and retaining elements, which fix the projection of the housing within the stent of the cuff forming a quick-dismountable junction of the housing with the cuff.
This heart valve prosthesis, chosen as prototype, provides the possibility to install it easily and safely and, in case of valve dysfunction, the possibility to replace it without removal of its cuff. However, it is possible to modernize this prosthesis in order to increase its safety of use and reliability.
The objective of the proposed invention is to reduce risk of trauma to the patient during reimplantation of the heart valve prosthesis and increase reliability of the implanted prosthesis.